Strange Problem

[:: cmckay ::]

Not sure where to post this so went with GH.

I have a stange scratching noise coming from my speakers, its nothing to do with any cables or interfance that I can see.

What I have noticed is that when the computer is doing / processing something the noise if more frequent and louder. If the machine isn't doing anything you can bearly hear it or it isn't there at all sometimes.

This comes and goes. Any ideas what would cause this?

 

[:: cmckay ::]

Its on-board sound. Musting any of the audio options doesn't help, and changing the volume doesn't affect how lound it is etc..

PSU and speakers are connected to 2 seperate surge protectors, so not that unfortunatly.

Thanks

 

[:: cmckay ::]

The machine is a Dell Dimension 3100.